when the 1934 Flying Eagle Original Radiator Cap was tightened down on the radiator what controlled the pressure.

[ December 28, 2001: Message edited by: 1931 Greaser ]

Nothing! The '34 cooling systems were not pressurized.

The first year for a pressurized cooling system in a Chevrolet was 1948 and not again until 1950 or 1951 I think.

Yep, nothing. The water pump actually pumps the water quicker than what the rest of the system can keep up with.
I know that you have to add extra or thicker fibre washers to get the caps to fit firmly.

I'm currently looking at the possibilty of putting a steel round type block in the top radiator hose, with holes in the steel round type block to slow up the water preasure.
My 34 water level once hot, rises pretty high up and if I have 'too much water' it spews out under the cap...and all down my nice shiny paint work...sniff

Hi Steve - There was an article in the G&D several years ago about 4 cyl Chevy cooling and a copper tubing solder type end cap that just fits in the top hose was used. It was drilled to 3/8 in. I use a Gano Filter which has about the same restriction and you'd be surprised how many flakes of rust and small rocks I found in the first 100 miles.
Herb

I can remember my Grandfather putting a big fender washer with a 1/2 hole in the upper radiator hose to slow down the flow in his 33 Sedan.


Kirk